Implantable medical devices (IMDs) may be used to treat a variety of medical conditions. Some IMDs may include medical leads for sensing and/or delivery of electrical stimulation therapy to a patient via implanted electrodes. For example, an electrical stimulation device may include an implantable electrical stimulation generator and one or more implantable leads carrying electrodes. In some cases, implantable electrodes may be coupled to an external electrical stimulation generator via one or more percutaneous leads or fully implanted leads.
Example IMDs that may include medical leads include neurostimulators, cardiac monitors, cardiac defibrillators, cardiac pacemakers, and others. Electrical stimulation therapy may include stimulation of nerve, muscle, or brain tissue, or other tissue within a patient. An electrical stimulation device may be fully implanted within the patient. Medical electrical stimulators have been proposed for use to relieve a variety of symptoms or conditions such as heart disease, chronic pain, tremor, Parkinson's disease, depression, epilepsy, migraines, urinary or fecal incontinence, pelvic pain, sexual dysfunction, obesity, and gastro paresis. An electrical stimulator may be configured to deliver electrical stimulation therapy via medical leads that include electrodes implantable proximate to the heart, spinal cord, pelvic nerves, gastrointestinal organs, peripheral nerves, or within the brain of a patient. Stimulation proximate the spinal cord, within the brain, and proximate peripheral nerves are often referred to as spinal cord stimulation (SCS) deep brain stimulation (DBS), and peripheral nerve stimulation (PNS), respectively.